
select count(*) into v_count from bpa_df_role where drename=record_drename and ddnid=ddnid_new
if v_count=0
then
select dreid into dreid_new from bpa_df_role where drename=record_drename and ddnid=ddnid_new
update....
else
update...
end if
end
类似这样处理吧,得前边定义一个v_count的变量,百度这个换行换的真难看,能看懂吧?
不过update后必须要提交,要不重新进来,还是未更改状态
使用SELECT INTO进行备份与MYSQLDUMP很相似,同样是把数据库备份到一个指定的文件中。其结果文件只能被建立在MySQL服务器上,而不是任何其他主机。SELECT INTO语句的语法格式如下:
Select … into outfile 'path_and_filename'
示例:
使用SELECT INTO语句查询数据库“mr_mysql”中的“mr_gly”表,把该表备份到“D:\\gly.txt”目录下,文件的名称是“gly.txt”。
mysql>use mr_mysql
Database changed
mysql>select * from mr_gly into outfile "D:\\gly.txt"
Query OK, 5 rows affected (0.00 sec)
下面的这些参数是SELECT INTO语句的非默认参数。
[fields
[terminated by '\t' ] //设置输出文件以什么作为分界标识
[enclosed by '' ] //指定的字符包围了所有的域
[[optionally] enclosed by '' ] //指定只有字符域被包括
[escaped by '\\'] ]
[lines terminated by '\n' ] //设置长行的中断被什么字符代替
下面是应用了SELECT INTO语句非默认参数的几个示例。
示例:
在每个域之间,默认的制表符被字符“|”代替。
mysql>use tpsc
Database changed
mysql>select * from jtsr into outfile "D:\\user1.txt" fields terminated by '|'
Query OK, 5 rows affected (0.00 sec)
示例:
Enclosed关键字用指定的字符“双引号”包围了所有的域。
mysql>select * from jtsr into outfile "D:\\user2.txt" fields terminated by '|' enclosed by '"'
Query OK, 5 rows affected (0.02 sec)
示例:
Optionally关键字的使用,导致了只有字符域被双引号包括。
mysql>select * from jtsr into outfile "D:\\user3.txt" fields terminated by '|' optionally enclosed by '"'
Query OK, 5 rows affected (0.02 sec)
示例:
lines terminated的使用,使每行之间的中断被字符“\n”
代替。
mysql>select * from jtsr into outfile "D:\\user4.txt" fields terminated by '|' lines terminated by '\n'
Query OK, 5 rows affected (0.02 sec)
示例:
综合使用这些参数。
mysql>select * from jtsr into outfile "D:\\user5.txt" fields terminated by '|' optionally enclosed
by '"' lines terminated by '\n'
Query OK, 5 rows affected (0.02 sec)
示例:
使用SELECT语句中的条件进行备份。
mysql>select * from jtsr where id>3 into outfile "D:\\user6.txt" fields terminated by '|' optionall
y enclosed by '"' lines terminated by '\n'
Query OK, 2 rows affected (0.01 sec)
注意:在使用SELECT INTO语句时,为备份的文件命名时切忌不要重写已存在的文件在编写文件输出的位置时不要忘记使用换码符“\”。
欢迎分享,转载请注明来源:内存溢出
微信扫一扫
支付宝扫一扫
评论列表(0条)